Method of operating auger ice-making machine

ABSTRACT

A method of operating an auger ice-making machine having a refrigeration casing, an auger screw rotatably disposed inside the casing and feeding, while scraping, the ice frozen on an inner wall surface of the casing, a stocker for storing/retaining the ice fed, the stocker being formed with an ice discharge port of the stocker in order to discharge the ice to an exterior of the machine by being opened, and a stored-ice detector for detecting a high level, and a low level, of a quantity of ice stored within the stocker, wherein: when the stored-ice detector detects the high level, a controller is activated to stop ice-making operation, and when the quantity of ice stored decreases below the low level by a required quantity, the controller restarts the ice-making operation; and when the controller judges, during a stopped state of the ice-making operation, that a block of ice has occurred in the stocker, the controller restarts the ice-making operation, provided that the stored-ice detector has detected the low level.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method of operating an auger ice-makingmachine, and more particularly, to a method of operating an augerice-making machine which feeds by means of an auger screw, whilescraping, the ice frozen on an inner wall surface of a refrigerationcasing, compresses the frozen ice by means of a push head, and stores ina stocker the compressed ice obtained.

2. Description of the Related Art

In the kitchens of coffee shops, restaurants, and the like, ice-makingmachines for manufacturing blocks of ice of required shapes have beenconveniently used for a long time, and these types of machines includean auger type of ice-making machine used for continuously manufacturingblocks of ice in the form of small pieces such as ice chips or iceflakes. In the auger ice-making machine, when ice-making operation isstarted with ice-making water stored within a cylindrical refrigerationcasing at a required level, the casing is forcedly cooled by arefrigerant circulating through an evaporation pipe connected to arefrigerating system. Hence, the ice-making water starts freezingprogressively from an inner wall surface of the casing, and thus thinice of a laminar form is formed. The refrigeration casing has an augerscrew inserted thereinto, and when the auger screw is rotationallydriven by an auger motor, the thin ice frozen on the inner wall surfaceof the casing is fed upward by the auger screw while being scraped intoa flake form thereby. While passing through a push head disposed in anupper inner section of the refrigeration casing, the flake-form ice fedby the auger screw is compressed, whereby moisture is removed from theice and compressed ice (ice) is manufactured. The compressed ice thathas thus been obtained is discharged and stored in a stocker.

The foregoing auger ice-making machine has, inside the above stocker,stored-ice detection means including a reed switch capable of detectinga storage level of compressed ice, and is adapted to store a requiredquantity of compressed ice in the stocker at all times. This isaccomplished by conducting control so that when the switch turns on toindicate that the detection means has detected a full state (high level)of the compressed ice in the stocker, ice-making operation is stopped,and so that when the switch turns off to indicate that the detectionmeans has detected a decrease in the quantity of compressed ice withinthe stocker to a required level (low level) due to ice consumption(discharge from the stocker), the ice-making operation is restarted.

However, the differential between the high level and low level detectedby the stored-ice detection means is limited to a small value, and afterdetection of the high level (i.e., the stop of the ice-makingoperation), the low level resulting from slight melting of thecompressed ice or from a small quantity of discharge thereof is detectedprior to the restart of the ice-making operation. After this, since asmall quantity of compressed ice is only added during the ice-makingoperation, a full state (high level) is detected soon and the ice-makingoperation stops. In this case, compressed ice in an incompletelysolidified condition is stored in the stocker initially during therestart of the ice-making operation. Accordingly, if the start and stopof the operation are repeated within a short time period by such controlas described above, the quantity of compressed ice in an incompletelysolidified condition (so-called scrap ice) in the stocker progressivelyincreases. Since such scrap ice is very soft, it sticks to the innerwall surface of the stocker in the form of a donut, then changing into ablock of ice, thus impeding the discharge of compressed ice. Inaddition, a full-state detection failure could result if the block ofice grows to a level at which the stored-ice detection means isdisposed. Therefore, if ice-making operation is continued in that stateor the machine remains exposed to a cryogenic atmosphere, the entirestocker encounters the serious trouble of freezing. Furthermore, notonly the compressed ice could not only become a mass too large to bedischarged from the stocker, but also is indicated the likelihood ofdamage being caused to the auger motor and other ice-making mechanicalsections by significant loading.

For these reasons, Japanese Unexamined Patent Publication No.2001-141344, for instance, proposes a technology for preventing theabove-mentioned repetition of start/stop of ice-making operation withina short time period and hence the occurrence of various trouble,associated with the above-mentioned increase in the quantity of scrapice, by setting the restarting timing of the operation, based oncombined use of the storage level of the compressed ice inside thestocker and other parameters.

According to the technology disclosed in the above Patent Publication,the machine is constructed so as to start counting a previously setdelay time (one of the other parameters mentioned above) from the timethat the stored-ice detection means detects that the quantity ofcompressed ice in the stocker has been reduced to a low level byconsumption, and restart ice-making operation after the delay time haselapsed. In this case, if the stored-ice detection means is maintainedin a full-stocker-state (high-level) detection condition by theoccurrence of a block of ice in the stocker, even when the compressedice is discharged from the machine or melts during that time, countingof the delay time is not started since the stored-ice detection meansdoes not detect a low level. Therefore, the quantity of compressed iceis likely to have significantly decreased by the time the block of icemelts and collapses to cause the stored-ice detection means to detect alow level. Consequently, a shortage of ice could occur since the stockerwill have become empty by the time a subsequent delay time elapses.

In addition, although the stocker of the foregoing ice-making machine isheat-insulated, melting of the compressed ice in the stocker with timereduces the storage level, and even if the compressed ice is notdischarged, the low level may be detected. Furthermore, the speed atwhich the ice melts is affected by the ambient temperature of thelocation at which the ice-making machine is installed, and the meltingspeed of the ice greatly differs between, for example, the wintertimeand the summertime. In this case, for example, if the above-mentioneddelay time is set to take a small value fit for the time of the yearwhen ice rapidly melts, such as in the summer, the effect of providingthe delay time is not obtainable at the time of the year when ice meltsslowly, as in the winter. This is because, despite only a slightquantity of compressed ice decreasing, ice-making operation is restartedand such scrap ice as mentioned above increases. Conversely, it isindicated the problem that if the above-mentioned delay time is set totake a large value fit for the time of the year when ice slowly melts,such as in the winter, the stocker runs out of compressed ice at thetime of the year when ice melts rapidly, as in the summer. It becomesnecessary for a user, therefore, to perform troublesome and complexoperations to optimize the setting of the above delay time according tothe particular ambient temperature. If stored-ice detection means fordetecting a high level and stored-ice detection means for detecting alow level are disposed spacedly in a vertical direction and thedifferential between both levels is set to take a large value,repetition of the start/stop of operation within a short time period canbe prevented without adjusting the delay time. In this case, however,the number of stored-ice detection means increases, thereby increasingcosts, disadvantageously.

SUMMARY OF THE INVENTION

A controller conducts control, provided that when stored-ice detectionmeans detects a high level (H), the controller stops ice-makingoperation, and that when actual ice decrement quantity G has exceeded apreviously set initial operating quantity of ice, C, the controllerrestarts the ice-making operation. In addition, when a total icedischarge time of T6 by an ice discharge timer for counting the timeduring which compressed ice is discharged from an ice discharge port ina stopped state of the ice-making operation increases above apreviously-set required time of T7, if the stored-ice detection meansdetects high level H, the controller judges that a block of ice isoccurring. Subsequently, when the stored-ice detection means detects alow level (L), the controller restarts the ice-making operation,irrespective of the value of actual ice decrement quantity G.

When the stored-ice detection means detects high level H, the controllerstops the ice-making operation. A unit quantity of molten ice, F, iscalculated from a reference time count of T1 up to detection of lowlevel L by the stored-ice detection means, and from a reference quantityof ice storage, D. A total quantity of molten ice, B, is calculated fromthe unit quantity of molten ice, F, and an actual time count of T3. Thecontroller restarts the ice-making operation, provided that actual icedecrement quantity G that is a sum of the total quantity of molten ice,B, and a total quantity of ice discharge, A, has exceeded the previouslyset initial operating quantity of ice, C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an auger ice-making machine towhich is applied an operating method according to a first embodiment ofthe present invention;

FIG. 2 is a main flowchart applied when an auger ice-making machine isoperated using the operating methods according to the first embodimentand a second embodiment;

FIG. 3 is a flowchart for calculating a unit quantity of ice melting iceper unit time during the operations using the operating methodsaccording to the first embodiment and the second embodiment;

FIG. 4 is a flowchart for coping with the occurrence of a block of iceduring operations using the operating method according to the firstembodiment;

FIG. 5 is a schematic diagram showing an auger ice-making machine towhich is applied the operating method according to the second embodimentof the present invention;

FIG. 6 is a schematic diagram showing an auger ice-making machine towhich is applied an operating method according to a third embodiment ofthe present invention; and

FIG. 7 is a graphic diagram showing the relationship between a unitquantity of molten ice and temperature.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Next, methods of operating an auger ice-making machine according topreferred embodiments of the present invention are described belowreferring to the accompanying drawings.

FIG. 1 shows a schematic configuration of an auger ice-making machine towhich is applied an operating method according to a first embodiment ofthe present invention. In FIG. 1, the auger ice-making machine has, onan outer surface of a cylindrical refrigeration casing 10, anevaporation pipe (evaporation section) 12 communicating with arefrigerating system is tightly wound, and the machine is adapted toforcibly cool the refrigeration casing 10 by circulating a refrigerantthrough the evaporation pipe 12 when ice-making operation is started. Inaddition, the refrigeration casing 10 is adapted so that when ice-makingwater is supplied from an ice-making water tank (not shown) at arequired level and ice-making operation is started, the refrigerationcasing 10 is forcibly cooled. Hence, the ice-making water startsfreezing gradually from an inner wall surface of the casing, and thusthin ice of a laminar form is formed.

Inside the refrigeration casing 10, an auger screw 14 is inserted, alower shaft 14 a thereof is rotatably supported by a lower bearing 16disposed at a lower section of the refrigeration casing 10, and an uppershaft 14 b is rotatably supported by a push head 18 disposed in an upperinner section of the refrigeration casing 10. The auger screw 14 isrotationally driven by an auger motor 20 disposed at a lower section ofthe ice-making machine. In addition, a scraping cutter blade 14 c withan outside diameter slightly smaller than an inside diameter of therefrigeration casing 10 is helically formed on the auger screw 14, andthe thin ice frozen on the inner wall surface of the casing 10 is fedupward while being scraped by the scraping cutter blade 14 c of theauger screw 14 rotationally driven by the auger motor 20.

During its passage through the push head 18, the flake-like ice fedupward by the auger screw 14 while being scraped is then compressed,whereby moisture is removed from the ice and compressed ice ismanufactured. The compressed ice that has thus been obtained isdischarged and stored in a stocker 22 disposed at an upper section ofthe refrigeration casing 10.

Inside the stocker 22, a stirrer 24 coupled with the auger screw 14 isrotatably disposed and is adapted to rotate with the auger screw to stirthe compressed ice stored within the stocker 22. The stocker 22 alsointernally has an ice discharge port 26, which is opened and closed by ashutter 28. When an ice discharge button not shown is pressed (turnedon), the shutter 26 is actuated by a controller 30 (described later).Thus, the ice discharge port 26 is opened, the stirrer 24 rotates, andthe compressed ice inside the stocker 22 is discharged from the icedischarge port 26 to an exterior of the machine.

The above-mentioned auger ice-making machine has a controller 30 ascontrol means of undertaking total electrical control of the machine,and the machine uses the controller 30 to control the operation of theice-making mechanism constituted by a compressor, a fan motor, an augermotor 20, and other elements. The controller 30 is also adapted not onlyto conduct opening/closing control of the shutter 28, but also tomonitor a quantity of ice discharged from the ice discharge port 26(i.e., a total quantity of ice discharge, A), on the basis of anopen-state duration of the shutter 28. In addition, as described later,the controller 30 is set to monitor a quantity of compressed ice meltinginside the stocker 22, as a quantity of molten ice (a total quantity ofmolten ice, B), and conducts operation control of the ice-makingmachine, based on the total quantity of ice discharge, A, and the totalquantity of molten ice, B.

The stocker 22 also internally has, at its ceiling, a float plate 32disposed in a vertically movable condition, and the float plate 32 isadapted to move vertically according to a quantity of compressed icedischarged from the push head 18 into the stocker 22 (i.e., according toa particular storage level of the ice). In addition, the stocker 22 hasa stored-ice detector 34 for detecting low level L and high level H asstorage levels of the ice within the stocker by detecting verticalmovements of the float plate 32. That is to say, when the compressed iceis discharged from the push head 18 into the stocker 22, the storagelevel increases, and then when the float plate 32 is pushed upward bythe compressed ice and reaches high level H related to a previously setfull state, the stored-ice detector 34 detects high level H and theresulting high-level signal is input to the controller 30. When thecompressed ice is reduced in storage level by being discharged from thestocker 22 to the machine exterior or by melting and the float plate 32thus moves downward to previously set low level L, the stored-icedetector 34 detects low level L and the resulting low-level signal isinput to the controller 30. During the time from completion of detectionof high level H to detection of low level L, the stored-ice detector 34inputs the above-mentioned high-level signal to the controller 30. Forexample, a reed switch as the stored-ice detector 34, turns on when itdetects high level H, and turns off when it detects low level L.

When the high-level signal is input from the stored-ice detector 34, thecontroller 30 stops the operation (ice-making operation) of theice-making machine by turning off the auger motor, the compressor, andthe fan motor. After input of the high-level signal, the controller 30conducts control to restart the ice-making machine, provided that actualice decrement quantity G that is a sum of the total quantity of moltenice, B, and the total quantity of ice discharge, A, has exceeded apreviously set initial operating quantity of ice, C. In addition, thecontroller 30 has a measuring timer 36 that starts counting when thestored-ice detector 34 detects high level H, and an accumulative timer38 that accumulates an open-state duration of the ice discharge port 26(i.e., an ice discharge time). The stored-ice detector 34 calculates thetotal quantity of molten ice, B, and the total quantity of icedischarge, A, from a time count of the measuring timer 36 and anaccumulative time count of the accumulative timer 38. Incidentally, theaccumulative timer 38 is set so that it accumulatively counts a time(seconds) for which a user presses an ice discharge button.

To the controller 30 are input beforehand a reference quantity of icestorage, D (the quantity of compressed ice stored during the time fromdetection of low level L by the stored-ice detector 34 to detection ofhigh level H thereby), and a unit quantity of ice discharge, E (thequantity of compressed ice discharged from the ice discharge port 26 perunit time). The reference quantity of ice storage, D, and the unitquantity of ice discharge, E, are calculated from the test resultsobtained beforehand. The controller 30 then calculates a unit quantityof molten ice, F (the quantity of ice melting per unit time), from thereference quantity of ice storage, D, and a reference time count of T1by the measuring timer 36 from the stop of the ice-making operation todetection of low level L by the stored-ice detector 34. In addition, thecontroller 30 is adapted to calculate the total quantity of molten ice,B, from an actual time count of T3 which indicates the time from theoperation stop based on the measuring timer 36, and the unit quantity ofmolten ice, F. Furthermore, the controller 30 is adapted to calculatethe total quantity of ice discharge, A, from the unit quantity of icedischarge, E, and an accumulative open-state duration count T2 of theice discharge port 26 by the accumulative timer 38. As described above,the controller 30 is set so that, provided that actual ice decrementquantity G (i.e., the sum of the total quantity of molten ice, B, andthe total quantity of ice discharge, A) has exceeded the previously setinitial operating quantity of ice, C, the controller provides control torestart the ice-making machine.

The initial operating quantity of ice, C, serves as a criterion forjudging how far the quantity of compressed ice needs to go down beforeice-making operation can be restarted from its stoppage due to detectionof high level H by the stored-ice detector 34. The initial operatingquantity of ice, C, is set from a capacity of the stocker 22 and otherparameters such as a sufficient operating time required for solidcompressed ice to be manufactured after the restart of the ice-makingoperation, and the setting is then input to the controller 30beforehand. Also, the initial operating quantity of ice, C, is set totake a greater value than the reference quantity of ice storage, D, suchthat the ice-making operation is restarted when the ice storage level(quantity of ice storage) in the stocker 22 decreases by a requiredvalue below low level L.

When the unit quantity of molten ice, F, is to be calculated, ifcompressed ice is discharged from the ice discharge port 26 by a pressof the ice discharge button during the time from the stop of theice-making operation by the detection of high level H by the stored-icedetector 34 to the detection of low level L thereby, a correct valuecannot be obtained by calculating the unit quantity of molten ice, F, byuse of the reference quantity of ice storage, D. When calculating theunit quantity of molten ice, F, therefore, the controller 30 uses thevalue obtained as a new reference quantity of ice storage, D1, bysubtracting the unit quantity of ice discharge, E, and the open-stateduration count by the accumulative timer 38, from the reference quantityof ice storage, D.

Furthermore, before actual ice decrement quantity G exceeds the initialoperating quantity of ice, C, when actual time count T3 by the measuringtimer 36 reaches or exceeds a previously set maximum time of T4, thecontroller 30 restarts the ice-making operation in preference to therelationship between actual ice decrement quantity G and the initialoperating quantity of ice, C. Besides, the controller 30 maintains thestopped state of the ice-making operation until actual time count T3 bythe measuring timer 36 has reached or exceeded a previously set minimumtime of T5.

The controller 30 has an alarm lamp 40 connected as alarm means, and isadapted so that even after the total quantity of ice discharge, A, hasexceeded the initial operating quantity of ice, C, if the stored-icedetector 34 does not detect low level L, the controller 30 activates thealarm lamp 40 to alarm the user of the fact that an abnormality isoccurring.

At this time, if the block of ice that has occurred in the stocker 22makes the float plate 32 unable to move downward from high level H andthus the stored-ice detector 34 is maintained in a detection state ofhigh level H, the above-described problem arises since the quantity ofcompressed ice is likely to have decreased significantly by the time thestored-ice detector 34 detects low level L as a result of, as describedabove, the block of ice melting and collapsing. In the auger ice-makingmachine according to the present embodiment, therefore, the controller30 has an ice discharge timer 44 that accumulatively counts the time(seconds) during which the user is pressing the ice discharge button.When a total ice discharge time of T6 counted by the ice discharge timer44 becomes equal to or exceeds a previously-set required time of T7, ifthe stored-ice detector 34 detects high level H, the controller 30judges that a block of ice is occurring in the stocker, and consequentlyconducts abnormal-operation control.

The required time of T7 is set to ensure that under the relationshipbetween the reference quantity of ice storage, D, of compressed iceduring the time from high level H and low level L, and the unit quantityof ice discharge, E (the quantity of ice discharged from the icedischarge port 26 per unit time), the quantity of ice discharged duringthe required time of T7 is greater than the reference quantity of icestorage, D. In other words, despite the fact that after the stored-icedetector 34 has detected high level H, if the total ice discharge timeof T6 is equal to or exceeds the required time of T7, the stored-icedetector 34 must have, of course, detected high level H, if high level Hstill remains detected, this means that the float plate 32 is judgedunable to move below high level H because of the block of ice beingpresent.

Next, the operation of the method of operating an auger ice-makingmachine according to the above first embodiment is described below withreference to the flowcharts of FIGS. 2 to 4.

As shown in FIG. 2, when a power supply switch for starting theabove-mentioned auger ice-making machine is turned on, whether thestorage level of compressed ice in the stocker 22 is “high level H” isconfirmed in step S1. If judgment results are negative (NO), water issupplied to the refrigeration casing 10 in step S2 and then ice-makingoperation is started in step S3. That is, the auger motor 20 and thecompressor, fan motor, and other elements constituting the ice-makingmechanism are started.

When ice-making operation is started, the refrigeration casing 10 isforcedly cooled by exchanging heat with the refrigerant circulatedthrough the evaporation pipe 12. Consequently, the ice-making watersupplied from an ice-making water tank (not shown) to the refrigerationcasing 10 starts freezing gradually from the inner wall surface of thecasing, and thin ice of a laminar form is formed. Next, the thin ice isfed upward while being scraped by a scraping cutter blade 14 c of theauger screw 14 rotationally driven by the auger motor 20. The flake-likeice fed upward by the auger screw 14 is then compressed while beingpassed through the push head 18 disposed in an upper internal section ofthe refrigeration casing 10, and the compressed ice that has thus beenobtained is discharged and stored into the stocker 22.

After the storage level of the compressed ice in the stocker 22 hasincreased and the float plate 32 has been pushed upward to make thestored-ice detector 34 detect high level H, YES is presented as positiveconfirmation results in step S1, the process proceeds to step S4 to makethe measuring timer 36 start counting, and the ice-making operation isstopped in step S5. That is, the auger motor 20, the compressor, the fanmotor, and other ice-making mechanical sections are stopped.

During the stop of the ice-making operation, a press (turn-on) of theice discharge button by the user discharges the compressed ice from thestocker 22. More specifically, when the ice discharge button is pressed,the shutter 28 is actuated by the controller 30 to open the icedischarge port 26 and thus to discharge the compressed ice therefrom. Atthis time, the auger motor 20 is rotationally driven to rotate thestirrer 24 and accelerate the discharge of the compressed ice, and thetime during which the ice discharge port 26 is open is counted by theaccumulative timer 38. The time during which the ice discharge port 26is open during a pressed (turned-on) state of the ice discharge buttonis also counted by the ice discharger timer 44. During the stop of theice-making operation, the compressed ice inside the stocker 22 naturallymelts stepwise by being affected by the ambient temperature. In otherwords, although the quantity of compressed ice in the stocker 22 ismaintained at “high level H” during the stopped state of the ice-makingoperation, the discharge of the compressed ice by the user and naturalmelting of the compressed ice with time lead to gradual decreases in thestorage level.

In step S6 of FIG. 2, the quantity of compressed ice discharged from thestocker 22 to the machine exterior is calculated. That is, the totalquantity of ice discharge, A, is calculated from the value previouslyinput to the controller 30, i.e., the unit quantity of ice discharge, E(the quantity of ice discharged from the ice discharge port 26 per unittime), and accumulative open-state duration count T2 of the icedischarge port 26 by the accumulative timer 38.

In next step S7, the total quantity of compressed ice naturally meltingin the stocker 22 is calculated as the total quantity of molten ice, B.Prior to the calculation of the total quantity of molten ice, B, whenhigh level H is detected by the stored-ice detector 34, the controller30 starts calculating the unit quantity of molten ice, F. That is, asshown in the flowchart of FIG. 3, the previously input referencequantity of ice storage, D, is set in step S21 and then a new referencequantity of ice storage, D1, is calculated in step S22 by subtracting,from the reference quantity of ice storage, D, the total quantity of icedischarge, A, that was obtained in step S6 of FIG. 2. If no compressedice is discharged in the stopped state of the ice-making operation, thenew reference quantity of ice storage, D1, becomes the same as thereference quantity of ice storage, D.

When the stored-ice detector 34 detects low level L, the unit quantityof molten ice, F, is calculated in step S23 of FIG. 3 from referencetime count T1 that is a time counted by the measuring timer 36 up to thedetection of low level L, and either the new reference quantity of icestorage, D1, calculated in step S22, or the previously set referencequantity of ice storage, D. The unit quantity of molten ice, F, iscommensurate with the ambient temperature at which the auger ice-makingmachine is installed. The unit quantity of molten ice, F, therefore,takes a large value when the ambient temperature is high as in thesummertime, and takes a small value when the ambient temperature is lowas in the wintertime.

In step S7 of FIG. 2, the total quantity of molten ice, B, i.e., thetotal quantity of melting of compressed ice up to the present, iscalculated from the unit quantity of molten ice, F, calculated in themanner mentioned above, and actual time count T3 that is the currenttime count by the measuring timer 36.

In next step S8, it is confirmed whether actual ice decrement quantity Gthat is the sum of the total quantity of ice discharge, A, and the totalquantity of molten ice, B, is in excess of the initial operatingquantity of ice, C, previously input to the controller 30. If theresults are NO, the process returns to step S5 in order to maintain thestopped status of the ice-making operation. This means that until actualice decrement quantity G has exceeded the initial operating quantity ofice, C, even when the stored-ice detector 34 detects low level L, thestopped status of the ice-making operation is maintained. Accordingly,the small differential of the stored-ice detector 34 makes it possibleto prevent the repetition of operation starting/stopping within a shorttime period and prevent the occurrence of scrap ice, and reduces a loadon the ice-making mechanism.

If the confirmation results in step S8 are YES (actual ice decrementquantity G is in excess of the initial operating quantity of ice, C),the process proceeds to next step S9, in which it is then confirmedwhether the storage level of the compressed ice in the stocker 22 is“low level L”.

If the confirmation results in step S9 are YES (the storage level of thecompressed ice is “low level L”), the measuring timer 36, theaccumulative timer 38, the total quantity of ice discharge, A, and thetotal quantity of molten ice, B, are all reset in step S10. The processthen returns to the first step S1 in order to repeat the flow describedabove. That is, when actual ice decrement quantity G exceeds the initialoperating quantity of ice, C, if the storage level of the compressed icein the stocker 22 is below “low level L”, the controller 30 starts(restarts) the ice-making operation. Since the unit quantity of moltenice, F, used as the base for calculating the total quantity of moltenice, B, is, as mentioned above, commensurate with the ambienttemperature at which the auger ice-making machine is installed,ice-making operation can always be started at a stable storage/retentionlevel, regardless of changes in the ambient temperature.

If the results in step S9 are NO, in step S11, an alarm device, such asthe alarm lamp 40, is activated to indicate the occurrence of anabnormality, and the machine itself is brought to an abnormal stop. Inother words, if, despite the fact that actual ice decrement quantity Ghas exceeded the initial operating quantity of ice, C, the stored-icedetector 34 does not detect low level L, the controller 30 judges thatarching due to freezing of the compressed ice within the stocker 22 iscausing an abnormality such as a downward movement failure in the floatplate 32. Resultingly, the controller 30 activates the alarm lamp 40 orthe like. In the state where low level L is not detected by thestored-ice detector 34, since the unit quantity of molten ice, F, is notcalculated, actual ice decrement quantity G at this time is composedonly of the value of the total quantity of ice discharge, A.

In the controller 30, before actual ice decrement quantity G and theinitial operating quantity of ice, C, are compared in accordance withthe flowchart of FIG. 2, process steps different from those of FIG. 2are performed to respond to the occurrence of a block of ice. That is,when the stored-ice detector 34 detects high level H and ice-makingoperation is therefore stopped in step S31 of FIG. 4, step 32 isconducted to confirm whether the ice discharge button has been turned on(the discharge of the compressed ice has been started), and if NO ispresented, step 32 is repeated. If the confirmation results in step S32are YES, since this means that ice discharge button has been turned onto start the discharge of the compressed ice, the process proceeds tostep S33 in order to start the counting operation of the ice dischargetimer 44.

Next, whether the total ice discharge time of T6 counted by the icedischarge timer 44 has reached the required time of T7 is confirmed instep S34. If the results are NO, the process proceeds to step S35 inorder to confirm whether the ice discharge button has been turned off,i.e., whether the discharge of the compressed ice has been stopped. Ifthe confirmation results in step S35 are NO, the process returns to stepS34. If the confirmation results in step S35 are YES (the ice dischargebutton has been turned off to stop the discharge of the compressed ice),the process proceeds to step S36 in order to stop the counting operationof the ice discharge timer 44.

Following this, step S37 is performed to confirm whether the storagelevel of the compressed ice in the stocker 22 is “low level L”, and ifthe results are NO, the process returns to step S32 in order to repeatthe above flow. If the confirmation results in step S37 are YES, theprocess proceeds to step S38 in order to reset the ice discharge timer44, and the process is terminated in step S39. That is, if the storagelevel of the compressed ice in the stocker 22 is below “low level L”with the total ice discharge time of T6 of the ice discharge timer 44not reaching the required time of T7 (i.e., with the confirmationresults in step S34 being NO), the controller 30 judges that the floatplate 32 is properly moving downward with decreases in the quantity ofcompressed ice. The controller 30 judges, therefore, that a block of iceis not occurring in the stocker 22. If NO is presented in step S37, theprocess returns to step S32 in order to repeat the above flow.

In contrast, if YES is presented in step S34, the process skips to stepS40 in order to confirm whether the storage level of the compressed icein the stocker 22 is “high level H”. If the confirmation results in stepS40 are NO, this indicates that the storage level is low L, and in thiscase, the controller 30 also judges that a block of ice is not occurringin the stocker 22, and the process proceeds to step S41 to terminate thecontrol.

However, if the confirmation results in step S40 are YES, the processproceeds to step S42, in which a block of ice is then judged present.That is, if the total ice discharge time of T6 is equal to or in excessof the required time of T7, this means that a greater quantity ofcompressed ice than the reference quantity of ice storage, D, is beingdischarged to the machine exterior. Therefore, the fact that, at thistime, the stocker 22 still remains at high ice storage level H indicatesthat a state in which the downward movement of the float plate 32 isbeing obstructed by a block of ice is judged to be occurring. In thiscase, the process then proceeds to step S43 and sets up a block-of-icewarning flag (F=1).

Next, whether the storage level of the compressed ice in the stocker 22is “low level L” is confirmed in step S44 and if the results are NO,step S44 is repeated. If the confirmation results in step S44 are YES,the ice discharge timer 44 is reset in step S45 and then in step S46,ice-making operation is started (restarted). This means that after thecontroller 30 has judged a block of ice to be present, when thestored-ice detector 34 detects low level L, the ice-making operation isimmediately started without a comparison being conducted between actualice decrement quantity G and the initial operating quantity of ice, C.Hence, when the block of ice melts and collapses and the stored-icedetector 34 detects low level L, the ice-making operation can bestarted, and until actual ice decrement quantity G has exceeded theinitial operating quantity of ice, C, the ice-making operation ismaintained in a stopped state, whereby a shortage of the compressed icecan be prevented.

Before actual ice decrement quantity G exceeds the initial operatingquantity of ice, C, if an actual time count of T3 by the measuring timer36 reaches or exceeds a previously set maximum time of T4 (for example,12 hours), the controller 30 starts the ice-making operation. If theambient temperature is low and there persists a state in which almost nocompressed ice inside the stocker 22 melts and neither is the compressedice discharged, since arching or blocking due to freezing of thecompressed ice inside the stocker 22 is prone to occur, the ice-makingoperation is started when the maximum time setting of T4 is reached.Consequently, the compressed ice inside the stocker 22 can be stirred byrotating the stirrer 24 to prevent the occurrence of arching orblocking.

At this time, after the stored-ice detector 34 has detected high levelH, if the power supply switch is turned off for some reason and then thepower supply switch is turned on again, although high level H remainsdetected by the stored-ice detector 34, it cannot be seen at whatposition between high level H and low level L the actual ice storagelevel is. However, the controller 30 judges that the ice storage levelin the stocker 22 is high level H, and conducts processing based on theflowchart of FIG. 2. In this case, an appropriate unit quantity ofmolten ice, F, or actual ice decrement quantity G cannot be calculated.The controller 30, therefore, conducts control for the stopped state ofthe ice-making operation to be maintained until the actual time count ofT3 by the measuring timer 36 has exceeded a previously set minimum timeof T5 (for example, 3 hours). It is thus possible to prevent ice-makingoperation from being started within a short time on the basis of aninappropriate unit quantity of molten ice, F, or actual ice decrementquantity G.

According to the first embodiment described above, it is possible to setappropriate startup timing of ice-making operation automaticallyaccording to a particular ambient temperature without adding a newstored-ice detection device. It is also possible to reduce costs, andthere is no need to change a delay time or to perform other suchtroublesome and complex operations as required in the conventionaltechnology. In addition, the occurrence of scrap ice is prevented, icequality improves as a result, and arching due to the occurrence of scrapice is suppressed. Furthermore, since the frequency of starting/stoppingthe ice-making machine decreases, a load on the ice-making mechanism isrelieved and longer-life operation is achieved, which, in turn, reducesstartup energy consumption and hence saves energy. Besides, even ifblocks of ice occur in the stocker 22, appropriate response is possibleand compressed ice can be prevented from lacking.

While a special ice discharge timer for block-of-ice countermeasures isprovided in the first embodiment, the above-mentioned accumulative timercan also be used as the ice discharge timer. In addition, in the firstembodiment, although ice-making operation is controlled so as to bestarted when an actual decrement of ice and an initial operatingquantity of ice are compared and the quantity of ice stored is smallerthan its low level by a required quantity, the ice-making operation maybe controlled so as to be started when the setting of a delay timerwhich starts counting at the time of low-level detection by theabove-mentioned stored-ice detector is reached to indicate that thequantity of ice stored has decreased below its low level by a requiredquantity.

In the first embodiment, although it is judged that when the total icedischarge time of the ice discharged from the ice discharge port is inexcess of a required time, if the stored-ice detector detects a highlevel, a block of ice is judged to have occurred, no compressed ice islikely to be discharged during a stopped state of ice-making operation.The controller may therefore be programmed so that a time at which agreater quantity of compressed ice than a reference quantity of icestorage is estimated to melt is taken as a required time, and that whena timer that starts counting from the time of stoppage of ice-makingoperation counts the required time, if the stored-ice detector detects ahigh level, a block of ice is judged to have occurred.

Next, a second embodiment of a method of operating an auger ice-makingmachine according to the present invention is described below referringto the accompanying drawings. FIG. 5 shows a schematic configuration ofan auger ice-making machine to which the operating method according tothe second embodiment is applied, and the basic configuration of themachine is the same as that described in FIG. 1. Basic operation flow isalso the same as that described earlier in relation to FIGS. 2 and 3.The unit quantity of molten ice, F, is likely to be incalculable if thequantity of ice discharge that is the quantity of compressed icedischarged from the ice discharge port 26 by a press of theabove-mentioned ice discharge button following the stop of ice-makingoperation exceeds the above-mentioned reference quantity of ice storage,D. If this condition is actually established, therefore, the controller30 is constructed so that a maximum value previously set and input tothe controller 30 (for example, a value assuming an ambient temperatureof 37° C.) is set as the unit quantity of molten ice, F. In addition, ifthe total quantity of ice discharge, A, that was calculated inabove-mentioned step S6 is in excess of the above-mentioned referencequantity of ice storage, D, the maximum value previously set and inputto the controller 30 is used as the unit quantity of molten ice, F.

FIG. 6 shows a schematic configuration of an auger ice-making machine towhich an operating method according to a third embodiment is applied.Since the basic configuration of the machine is the same as adopted inthe first and second embodiments described above, only differentsections are described below with the same numeral being assigned to thesame member.

The controller 30 in the auger ice-making machine according to the thirdembodiment has a temperature sensor 42 connected for detecting anambient temperature, a temperature Q detected by the sensor 42 beinginput to the controller 30. The controller 30 is adapted to calculate aunit quantity of molten ice (per unit time), FA, from the detectedtemperature Q.

That is, the applicant has experimentally found that as shown in FIG. 7,the unit quantity of molten ice, FA, of the compressed ice in thestocker 22 is proportional to an ambient temperature. The applicant hasalso verified that the unit quantity of molten ice, FA, at the ambienttemperature can be calculated from the product of the constant N (4.47)obtained from the approximated line of FIG. 5, and the detectedtemperature Q.

In the operating method of the third embodiment, when the stored-icedetector 34 detects high level H, the controller 30 calculates the unitquantity of molten ice, FA, that is the quantity of melting ofcompressed ice per unit time. That is, the unit quantity of molten ice,FA, commensurate with the current ambient temperature is calculated bymultiplying the temperature Q detected by the temperature sensor 42, andthe constant N. Subsequently, similarly to the operating method of thesecond embodiment described above, control is conducted so as to startice-making operation when actual ice decrement quantity G that is thesum of [(the total quantity of molten ice, B, derived from the unitquantity of molten ice, FA, and an actual time count of T3) and thetotal quantity of ice discharge, A] exceeds the initial operatingquantity of ice, C, previously input to the controller 30. Other controlis the same as in the second embodiment.

That is, the operating method of the third embodiment also yields thesame operational effects as those of the above-described secondembodiment. In addition, in the operating method of the thirdembodiment, constantly changing temperatures are detected and the unitquantity of molten ice, FA, at each of the temperatures is calculated.Adequate operation control is therefore possible, even in thesummertime, for example, when the ambient temperature is high because ofair conditioning remaining turned off during off-business hours and thetemperature is lowered during business hours by turning air conditioningon.

1. A method of operating an auger ice-making machine having: arefrigeration casing for freezing ice on an inner wall surface of thecasing; an auger screw, rotatably disposed inside the casing, forfeeding, while scraping, the ice frozen on the casing inner wallsurface; a stocker for storing/retaining the ice fed by the auger screw;and stored-ice detection means for detecting a high level, and a lowlevel, of a quantity of ice stored within the stocker; wherein ice isdischarged to an exterior of said ice-making machine when an icedischarge port formed in the stocker is opened; and said methodcomprising the ordered steps of: allowing the control means to judgethat a block of ice has occurred in the stocker when a total icedischarge time of the ice discharged from the ice discharge port reachesor exceeds a previously set required time required for discharging agreater quantity of ice than a reference ice storage quantity of the icestored during a time from detection of the low level to that of the highlevel, provided that the high level is detected by the stored-icedetection means, and then allowing the ice-making operation to berestated when the control means judges, during a stopped state of theice-making operation, that a block of ice has occurred in the stocker,provided that the stored-ice detection means has detected the low level.2. A method of operating an auger ice-making machine having: arefrigeration casing for freezing ice on an inner wall surface of thecasing; an auger screw, rotatably disposed inside the casing, forfeeding, while scraping, the ice frozen on the casing inner wallsurface; a stocker for storing/retaining the ice fed by the auger screw;and stored-ice detection means for detecting a high level, and a lowlevel, of a quantity of ice stored within the stocker, wherein ice isdischarged to an exterior of said ice-making machine when an icedischarge port formed in the stocker is opened, and said methodcomprising the ordered steps of: allowing control means for monitoring aquantity of discharge from the ice discharge port and a quantity ofmolten ice within the stocker to be activated to stop ice-makingoperation when the stored-ice detection means detects the high level;and the allowing the control means to restart the ice-making operation,provided that an actual ice decrement that is a sum of, a total quantityof ice discharge from the ice discharge port and a total quantity ofmolten ice within the stocker, has exceeded a previously set initialoperating quantity of ice.